1. Field of the Invention
The present invention relates to surgical anastomotic stapling devices. More particularly, the present invention relates to end to end anastomotic surgical staplers avoiding minimal constrictive area at the anastomosis site.
2. Background Information
Surgical staplers have been developed to assist and improve a wide variety of surgical procedures. Surgical staplers provide precision in the placement of staples as well as decrease the time of given surgical procedures. A wide variety of surgical staplers have been developed for vascular, gastric, esophageal and intestinal surgery, to name but a few. These known staplers are often used in anastomosis procedures. In performing surgical anastomotic stapling, generally the two pieces of lumen are attached by a ring of staples with a closed loop stapler. The anastomosis of the lumen may be performed in a side to side, side to end or end to end manner which describes the relative orientation of the lumen sections.
The surgical staplers for performing end to end anastomosis are generally intraluminal surgical staplers that fire a pair of staggered rings of staples. These types of surgical staplers are often referred to as EEA's, which stands for “End to End Anastomosis”. During this procedure, a circular knife blade is used to separate tissue which is held within the circular ring. The separated tissue is then removed with the stapler so that a circular opening within the lumen is completed along the surgical stapling line.
In performing these surgical procedures with EEA's it has become desirable to separate the anvil on which the staplers are clinched from the stapling head portion from which the staples are expelled. It has been typical in the past that the stapling head is attached to the anvil and the tissue is secured through a “purse stringed” gathering of tissue.
Generally, the tissue stapled together with an EEA leaves a smaller opening than the original lumen into which the anvil and stapler head were inserted. Frequently, it is desirable to provide an anvil which can be collapsed to introduce the anvil into the body through a relatively small incision. An example of a surgical stapler having a variable diameter anvil is illustrated in U.S. Pat. No. 4,505,414 disclosing an anvil, integral with a surgical stapler, which can be collapsed and inserted through a small incision in a patient's body and expanded outwardly after placement inside the patients body to staple the wall of an organ to the abdominal wall or an external tissue layer of the patient's body. The anvil is not detachable from the stapler and thus cannot provide a continuous stapler line, but rather applies a broken, discontinuous line to “tack” the tissue in a circular line. This patent also does not provide an anvil which can be placed remotely within the body for subsequent attachment to a stapler head.
Other examples of anvils which are capable of collapsing to a reduced diameter after stapling to facilitate removal from the body are shown in U.S. Pat. Nos. 4,752,024; 4,893,622; 4,700,703 and 4,903,697. These anvils are introduced into the body through a relatively large incision.
U.S. Pat. No. 5,239,639 also shows a collapsible anvil assembly and applicator instrument for a surgical stapler apparatus. U.S. Pat. No. 6,503,259 is relevant to the present invention in that it discloses a surgical anastomotic fastener array (10 in the '259 patent) comprising a plurality of fasteners (11 of the '259 patent) each having a tissue piercing element (12 of the '259 patent), wherein the fasteners are aligned in an annular array of a first diameter at least prior to anastomosis and are designed to expand to form an annular array of a second larger diameter and then contract as needed after anastomosis. The '259 patent is addressing the same broad concern of the resulting anastomotic ring, but the earliest filing date of the '259 patent is, however, not earlier than the conception date of the present invention.
The retractable anvil EEA's discussed above do not address the fundamental problem of the constrictive point formed after luminal anastomosis. These prior art devices simply address the problem of post operative tool removal.
It is the object of the present invention to avoid the drawbacks of the prior art by avoiding the minimal constriction formed at luminal anastomotic sites using anastomotic staplers (i.e., EEA's). It is a further object of the present invention to provide anastomotic staplers which are easy to manufacture and utilize. A further object of the present invention is to provide both intraluminal anastomotic end to end staplers and extraluminal anastomotic end to end staplers.